1. Field of the Invention
The present invention relates to a method for manufacturing a dispersion and a liquid mixing device.
2. Description of the Related Art
As functional materials included in dispersions, for example, there have been known agricultural chemicals, such as an herbicide and a pesticide, medicine, such as an anticancer agent, an antiallergic agent, and an antiphlogistic, and coloring materials contained, for example, in ink, toner, and color filters.
In addition, as the coloring materials contained in ink, toner, and the like, pigments have started to be used. In these situations, in order to obtain a superior pigment dispersion using a pigment, a pigment dispersing method using a microjet reactor has been proposed.
In US 2002/0040665 A1, a method for forming a suspension liquid of a pigment has been disclosed in which a solution containing a solvent and a crude pigment dissolved therein, and a precipitation medium, are sprayed and are allowed to collide with each other in a housing of a reactor chamber.
In addition, in US 2007/0149651 A1, a method for manufacturing a dispersion has been disclosed which includes a step of generating a reaction product by reaction between two types of liquids so as to form a dispersion including the reaction product dispersed in a dispersion medium.
In particular, in US 2007/0149651 A1, the two types of liquids are ejected from respective nozzles which are separately provided so that traveling directions of the liquids thus ejected intersect each other at an angle of 120° or less, and so that these liquids then flow in an integrated manner. Accordingly, a method for manufacturing a dispersion in which the reaction product is generated is disclosed.
In US 2002/0040665 A1, since the solution containing the pigment and the precipitation medium are sprayed frontally from respective nozzles facing each other and are mixed together, a liquid is splashed in the housing of the chamber.
In the case described above, it is supposed that the splashed liquid and/or reaction product adheres and deposits on an inside wall of the housing and then separates and peels off therefrom as the time passes.
In addition, the liquid or reaction product that separates and peels off may unfavorably cause a secondary reaction with liquids which are newly sprayed from the nozzles.
The disclosure of US 2007/0149651 A1 may be applied to the process of US 2002/0040665 A1, and discloses that since the splash of the liquid is suppressed, the secondary reaction caused thereby can be prevented, and a dispersion can be stably manufactured for a relatively long period of time.
Although the method described in US 2007/0149651 A1 is a contribution to this technical field, the technique described can still be improved. For example, according to the method disclosed in US 2007/0149651 A1, a dispersion including a reaction product having a relatively small particle diameter can be obtained; however, variation in the particle diameters still exists.